Large-Area Fabrication of a Highly Stable Wearable Temperature Sensing System via Dispensing Printing: Carbon-Based Electronic Ink, Self-Charging Sensing, and Remote Human Monitoring

With the rapid advancement of flexible electronics in healthcare diagnostics, real-time body temperature monitoring using electronic skin has become increasingly important for assessing and predicting human health status. Currently, most self-charging temperature sensing systems rely on thermoelectric effects, which are limited to transient detection and lack the resolution necessary to track subtle fluctuations in body temperature (e.g., <0.1 °C), thus constraining their practical use in wearable temperature monitoring. In this study, we developed a high-viscosity carbon-based electronic ink based on the synergistic interaction between 1D and 2D materials. Reduced graphene oxide (rGO) and multiwalled carbon nanotubes (MWCNTs) were used as active materials compatible with high-precision dispensing printing technology to fabricate flexible microtemperature sensors and microsupercapacitors (MSCs). The resulting temperature sensor, with a compact feature size, exhibited a high temperature coefficient of resistance (TCR = -1.08%) and fast response time (1.4 s), comparable to that of commercial rigid platinum-based thermometers. The serpentine electrode design and tightly packed internal structure imparted excellent stability under practical conditions, including encapsulation in insulating oil, mechanical deformation during motion, and repeated cycling. Furthermore, leveraging the versatility of printed electronics, we achieved a self-charging temperature sensing system based on the integrated microsupercapacitor. By incorporating IoT technologies and a bluetooth communication module, we realized real-time remote temperature monitoring, providing a promising platform for next-generation electronic skin in wearable wireless health diagnostics.